Use of an antibiotic-impregnated bone cement block in the revision of an infected shoulder arthroplasty

The incidence of shoulder arthroplasty infection presents a substantial economic burden in the United States: a predictive model

Background

Periprosthetic joint infections (PJIs) are a major cause of morbidity after shoulder arthroplasty. Prior national database studies have estimated the trends of shoulder PJI up to 2012.²¹ Since 2012, the landscape of shoulder arthroplasty has changed drastically with the expanding popularity of reverse total shoulder arthroplasty. The dramatic growth in primary shoulder arthroplasties is likely paralleled with an increase of PJI case volume. The purpose of this study is to quantify the rise in shoulder PJIs and the economic stress they currently place on the American healthcare system as well as the toll they will incur over the coming decade.

Methods

The Nationwide Inpatient Sample database was queried for primary and revision anatomic total shoulder arthroplasty, reverse total shoulder arthroplasty, and hemiarthroplasty from 2011-2018. Multivariate regression was used to predict cases and charges through the year 2030 adjusted to 2021 purchasing power parity.

Results

From 2011 to 2018, PJI was found to be 1.1% shoulder arthroplasties, from 0.8% (2011) to 1.4% (2018). Anatomic total shoulder arthroplasty experienced the greatest proportion of infections at 2.0%, followed by hemiarthroplasty at 1.0% and reverse total shoulder arthroplasty at 0.3%. Total hospital charges grew 324%, from $44.8 million (2011) to $190.3 million (2018). Our regression model projects 176% growth in cases and 141% growth in annual charges by 2030.

Conclusion

This study demonstrates the large economic burden that shoulder PJIs pose on the American healthcare system, which is predicted to reach nearly $500 million in charges annually by 2030. Understanding trends in procedure volume and hospital charges will be critical in evaluating strategies to reduce shoulder PJIs.

Antibiotic Spacers for Shoulder Periprosthetic Joint Infection: A Review

Periprosthetic joint infection is a rare but potentially devastating complication of shoulder arthroplasty. The most conservative treatment approach is a two-stage revision involving interval placement of an antibiotic cement spacer. The purpose of this study was to contextualize the use of antibiotic spacers in the current treatment paradigm of shoulder periprosthetic joint infection and to review the history of shoulder spacers, the different types (eg, stemmed versus stemless and prefabricated versus handmade), the antibiotic composition and dosage, and their efficacy and complications.

The impact of prior ipsilateral arthroscopy on infection rates after shoulder arthroplasty

BACKGROUND

Patients frequently undergo interventions before shoulder arthroplasty, including injections and arthroscopy. Although the potential impact of injections on postoperative outcomes such as infection has been well studied, it is less clear whether prior arthroscopy has an impact on infection rates after shoulder arthroplasty. The purpose of this study was to determine whether prior ipsilateral shoulder arthroscopy is associated with an increased risk of postoperative infection after shoulder arthroplasty.

METHODS

Patients who underwent shoulder arthroplasty, including hemiarthroplasty, total shoulder arthroplasty, or reverse shoulder arthroplasty with a minimum of 1-year preoperative database exposure, were queried using Current Procedural Terminology codes from 2 large insurance databases, including both private-payer (Humana, 2008-2017) and Medicare (2006-2014) data. Patients with procedures for infection, fractures, or without laterality data were excluded. Those who underwent ipsilateral shoulder arthroscopy within 2 years before their arthroplasty were identified and compared with controls who did not undergo prior arthroscopy. Each database was analyzed separately. Periprosthetic infection within 1 year after arthroplasty was queried for each group and compared using a logistic regression analysis with control for demographic and comorbidity confounders.

RESULTS

A total of 9362 Medicare patients and 17,716 private-payer patients were included in the study. Of these, 486 (5.2%) Medicare patients and 685 (3.9%) private-payer patients underwent prior arthroscopy. In the Medicare database, prior arthroscopy was also associated with a postarthroplasty infection rate of 3.9% as compared with 1.9% in the control group (odds ratio: 1.96, 95% confidence interval: 1.20-3.22, P = .003). Similarly, in the private insurance cohort, prior shoulder arthroscopy was associated with a postarthroplasty infection rate of 2.9% as compared with 1.4% in the control group (odds ratio: 1.85, 95% confidence interval: 1.13-3.03, P = .005).

CONCLUSION

Shoulder arthroscopy performed within 2 years before shoulder arthroplasty is associated with a higher infection rate in the first year after shoulder arthroplasty.

Advanced septic arthritis of the shoulder treated by a two-stage arthroplasty

BACKGROUND

The usual treatment of septic shoulder arthritis consists of arthroscopic or open lavage and debridement. However, in patients with advanced osteoarthritic changes and/or massive rotator cuff tendon tears, infection eradication can be challenging to achieve and the functional outcome is often not satisfying even after successful infection eradication. In such cases a two-stage approach with initial resection of the native infected articular surfaces, implantation of a cement spacer before final treatment with a total shoulder arthroplasty in a second stage is gaining popularity in recent years with the data in literature however being still limited.

AIM

To evaluate the results of a short interval two-stage arthroplasty approach for septic arthritis with concomitant advanced degenerative changes of the shoulder joint.

METHODS

We retrospectively included five consecutive patients over a five-year period and evaluated the therapeutic management and the clinical outcome assessed by disability of the arm, shoulder and hand (DASH) score and subjective shoulder value (SSV). All procedures were performed through a deltopectoral approach and consisted in a debridement and synovectomy, articular surface resection and insertion of a custom made antibiotic enriched cement spacer. Shoulder arthroplasty was performed in a second stage.

RESULTS

Mean age was 61 years (range, 47-70 years). Four patients had previous surgeries ahead of the septic arthritis. All patients had a surgical debridement ahead of the index procedure. Mean follow-up was 13 mo (range, 6-24 mo). Persistent microbiological infection was confirmed in all five cases at the time of the first stage of the procedure. The shoulder arthroplasties were performed 6 to 12 wk after insertion of the antibiotic-loaded spacer. There were two hemi and three reverse shoulder arthroplasties. Infection was successfully eradicated in all patients. The clinical outcome was satisfactory with a mean DASH score and SSV of 18.4 points and 70% respectively.

CONCLUSION

Short interval two-stage approach for septic shoulder arthritis is an effective treatment option. It should nonetheless be reserved for selected patients with advanced disease in which lavage and debridement have failed.

An Anatomic Intraoperatively Prepared Antibiotic Spacer in Two-Stage Shoulder Reimplantation for Deep Infection: The Potential for Early Rehabilitation

Molded antibiotic shoulder spacers allow for intraoperative customization of antibiotics and multiple size options. The purpose of this study was to evaluate the efficacy of an anatomic intraoperatively molded spacer in the two-stage treatment of infection and to assess the safety of early rehabilitation when the capsule and rotator cuff are present. During 2014 and 2015, 27 shoulders were treated with a molded antibiotic cement spacer as part of a two-stage treatment. Indications included periprosthetic joint infection (n=18), native shoulder infection (n=8), and infection after internal fixation (n=1). All patients were followed for a minimum of 2 years. Mean follow-up time was 29.6 months. Patients were allowed to perform motion exercises (group I; n=16) or were instructed to avoid motion (group II; n=11) after spacer implantation, depending on the condition of their rotator cuff. Infection was eradicated in 23 of the 27 shoulders (85%). At most recent follow-up, pain scores were lower in group I. Mean final elevation was 115° in group I compared with 93° in group II. Mean final active external rotation was 36°, with no difference between the groups. In 3 (4%) shoulders with significant proximal humeral bone loss, the spacer became rotationally unstable. An anatomic intraoperatively molded spacer can be implanted safely in two-stage treatment for deep infection and has a reasonable rate of eradication. When adequate capsule and rotator cuff tissue is present, early motion in between stages can be safely recommended with a trend toward improved forward elevation at final follow-up and may facilitate the second stage reimplantation. [Orthopedics. 2019; 42(4):211-218.].

Two-stage revision shoulder prosthesis vs. permanent articulating antibiotic spacer in the treatment of periprosthetic shoulder infections

INTRODUCTION

Periprosthetic shoulder infections (PSIs) represent a serious complication following shoulder arthroplasty. No consensus exists regarding the optimal option. We conducted a retrospective case-control study to compare the outcomes of 2-stage revision shoulder arthroplasty and those of definitive articulating antibiotic spacer implantation with regards to eradication of the infection, improvement of pain and shoulder function.

MATERIALS AND METHODS

Thirty patients treated for an infected shoulder arthroplasty were retrospectively reviewed after a mean follow-up of 8 years (range, 2-10 years). Nineteen underwent definitive articulating antibiotic spacer implantation and 11 underwent 2-stage revision arthroplasty. Mean age at surgery was 68.8 years. Assessment included Constant-Murley score, visual analog scale pain score, objective examination, patient subjective satisfaction score as well as standard radiographs.

RESULTS

At the most recent follow-up, none of the patients had clinical or radiographic signs suggesting recurrent infection. Most patients reported satisfying subjective and objective outcomes. Follow-up examination showed significant improvement of all variables compared to preoperative values (p<0.001). Radiographs did not show progressive radiolucent lines or change in the position of the functional spacer. No statistically significant differences were reported between the two groups concerning Constant-Murley and VAS scores, while average forward flexion and abduction were significantly higher in patients undergoing 2-stage revision surgery.

CONCLUSIONS

Both surgical procedures provided infection eradication and satisfying subjective functional outcomes. Functional results were superior in patients treated with revision shoulder prosthesis, although a higher rate of complication was reported in this cohort of patients, thus suggesting the use of permanent spacer in high-risk or low-demanding elderly patients.

LEVEL OF EVIDENCE

III, Retrospective case-control study.

Management of periprosthetic shoulder infections with the use of a permanent articulating antibiotic spacer

INTRODUCTION

Management of periprosthetic shoulder infections (PSIs) still remains challenging. We conducted a retrospective case study to assess the outcomes of definitive articulating antibiotic spacer implantation in a cohort of elderly, low-demanding patients. We hypothesized that in patients with low functional demands seeking pain relief with chronic PSIs, treatment with a definitive articulating antibiotic spacer would lead to satisfying results concerning eradication of the infection, improvement of pain, and improving shoulder function.

MATERIALS AND METHODS

19 patients underwent definitive articulating antibiotic spacer implantation for the treatment of an infected shoulder arthroplasty. Mean age at surgery was 70.2 years. Patients were assessed pre-operatively with functional assessment including Constant-Murley score, and objective examination comprehending ROM, visual analog scale pain score, and patient subjective satisfaction (excellent, good, satisfied, or unsatisfied) score. Radiographs were taken to examine signs of loosening, and change in implant positioning.

RESULTS

At the most recent follow-up, none of the patients had clinical or radiographic signs suggesting recurrent infection. Most patients reported satisfying subjective and objective outcomes. Follow-up examination showed significant improvement of all variables compared to pre-operative values (p < 0.001). Radiographs did not show progressive radiolucent lines or change in the position of the functional spacer. In one case, glenoid osteolysis was reported, which did not affect the clinical outcome.

CONCLUSIONS

In selected elderly patients with low functional demands seeking pain relief with infected shoulder arthroplasty, definitive management with a cement spacer is a viable treatment option that helps in eradicating shoulder infection and brings satisfying subjective and objective outcomes.

LEVEL OF EVIDENCE

Case series, Level IV.

Two-stage revision of infected shoulder arthroplasty using prosthesis of antibiotic-loaded acrylic cement: minimum three-year follow-up

PURPOSE

This study aimed to evaluate the clinical outcomes and persistent infection rate of two-stage revision of infected shoulder arthroplasty.

METHODS

We enrolled 12 patients who developed an infection after undergoing shoulder arthroplasty between January 2009 and January 2014. They underwent a two-stage revision with PROSTALAC implantation and shoulder re-implantation in the first- and second-stage surgery, respectively. The mean follow-up period was 40.88 months (range, 36-52 months). After the second-stage re-implantation, clinical scores, erythrocyte sedimentation rate, as well as C-reactive protein level were evaluated, and the presence of re-infection and complications were analyzed.

RESULTS

Infection was improved in all the cases after PROSTALAC insertion. The mean range of motion of forward elevation, external rotation, and internal rotation at the final follow-up after the second-stage re-implantation were 81.67°, 40.42°, and 16.67° (vertebral level), respectively. The mean visual analog scale score improved from 7.08 points before surgery to 2.33 points after surgery. The Modified American Shoulder and Elbow Surgeons score improved from 32.25 before surgery to 64.17 after surgery (P < 0.05). The Constant shoulder score also improved from 30.92 before surgery to 66.08 after surgery (P < 0.05). Infection had not recurred until the final follow-up. However, dislocation and separation of components were found in two patients who needed a structural allograft because of segmental bone defects.

CONCLUSION

Using PROSTALAC in two-stage revision arthroplasty is effective for infection control and produced good clinical outcomes after second-stage shoulder re-implantation. However, cases involving segmental bone defects require additional precautions in maintaining the appropriate tension and height to prevent complications.

The cost effectiveness of vancomycin for preventing infections after shoulder arthroplasty: a break-even analysis

BACKGROUND

Increasing methicillin resistance and recognition of Propionibacterium acnes as a cause of infection in shoulder arthroplasty has led to the adoption of local vancomycin powder application as a more effective method to prevent expensive periprosthetic infections. However, no study has analyzed the cost effectiveness of vancomycin powder for preventing infection after shoulder replacement.

METHODS

Cost data for infection-related care of 16 patients treated for deep periprosthetic shoulder infection was collected from our institution for the break-even analysis. An equation was developed and applied to the data to determine how effective vancomycin powder would need to be at reducing a baseline infection rate to make prophylactic use cost effective.

RESULTS

The efficacy of vancomycin (absolute risk reduction [ARR]) was evaluated at different unit costs, baseline infection rates, and average costs of treating infection. We determined vancomycin to be cost effective if the initial infection rate decreased by 0.04% (ARR). Using the current costs of vancomycin reported in the literature (range: $2.50/1000 mg to $44/1000 mg), we determined vancomycin to be cost effective with an ARR range of 0.01% at a cost of $2.50/1000 mg to 0.19% at $44/1000 mg. Baseline infection rate does not influence the ARR obtained at any specific cost of vancomycin or the cost of treating infection.

CONCLUSIONS

We have derived and used a break-even equation to assess efficacy of prophylactic antibiotics during shoulder surgery. We further demonstrated the prophylactic administration of local vancomycin powder during shoulder arthroplasty to be a highly cost-effective practice.

Use of a Functional Antibiotic Spacer in Treating Infected Shoulder Arthroplasty

Management of an infected shoulder arthroplasty remains challenging. Treatment goals include resolution of the infection, improvement in pain, and restoration of function. Two-stage revision with an antibiotic spacer and subsequent revision has shown variable success in achieving these goals. The practice of using a hemiarthroplasty and coating the stem with antibiotic cement without cementing the implant to the humerus (functional antibiotic spacer) during the first stage has the potential to achieve treatment goals without the need for a second revision. The goal of this study was to examine the outcomes of a maintained functional antibiotic spacer without a second revision for the management of infected shoulder arthroplasty. Fourteen patients with an infected shoulder arthroplasty underwent implantation of a functional antibiotic spacer, extensive surgical debridement, and a minimum of 6 weeks of treatment with postoperative intravenous antibiotics. The 9 patients who elected not to undergo revision surgery were included in this analysis. Pain scores, functional outcome scores, range of motion, strength, and patient satisfaction were measured for these patients at last follow-up and compared with preoperative scores. At an average follow-up of 25 months (range, 12-48 months), significant improvements were observed in functional outcome scores, shoulder abduction, and elevation, with a trend toward improvement in pain scores. One patient was unsatisfied with the result. No recurrent infection, progressive radiolucency, or change in position of the functional antibiotic spacer was observed. A functional antibiotic spacer effectively manages the infected shoulder arthroplasty while achieving significant improvements in function and motion. Patient satisfaction was high, with a relatively low rate of conversion to second-stage revision.

Periprosthetic shoulder infection in the United States: incidence and economic burden

BACKGROUND

Periprosthetic joint infection (PJI) is a major cause of morbidity after shoulder arthroplasty. PJI epidemiology has not been well studied. We aimed to analyze the historical incidence, predisposing factors, and economic burden of PJI after shoulder arthroplasty in the United States.

METHODS

Primary shoulder arthroplasty patients were identified by the International Classification of Diseases, Ninth Revision, Clinical Modification codes 81.80 (total shoulder arthroplasty), 81.81 (hemiarthroplasty), and 81.88 (reverse arthroplasty) in the Nationwide Inpatient Sample from 2002 to 2011. PJI was identified by codes 80.01 (arthrotomy for device removal) and 996.66 (prosthetic infection). Multivariate logistic regression analysis was used to identify predisposing factors for PJI.

RESULTS

PJI rate was 0.98% from 2002 to 2011 and did not vary significantly. Comorbidities associated with PJI were weight loss/nutritional deficiency (odds ratio [OR], 2.62; 95% confidence interval [CI], 1.53-4.51; P = .00047), drug abuse (OR, 2.38; 95% CI, 1.41-4.02; P = .0011), and anemia from blood loss (OR, 2.43; 95% CI, 1.50-3.93; P = .00031) or iron deficiency (OR, 2.05; 95% CI, 1.69-2.49; P < .0001). Demographic factors associated with PJI were younger age (OR, 1.020; 95% CI, 1.017-1.024; P < .0001) and male gender (OR, 1.961; 95% CI, 1.816-2.117; P < .0001). In 2011, median hospitalization costs for PJI were $17,163.57 compared with $16,132.68, $13,955.83, and $20,007.87 for total shoulder arthroplasty, hemiarthroplasty, and reverse arthroplasty, respectively.

CONCLUSION

Increasing incidence of shoulder arthroplasty and a constant infection rate will result in greater overall PJI burden. Whereas hospitalization costs for PJI are comparable to those of primary arthroplasty, they are incurred after the original cost of shoulder arthroplasty. Certain identifiable patient variables correlate with higher PJI rates. Risk factor modification may decrease PJI incidence and help contain costs.

A preformed antibiotic-loaded spacer for treatment for septic arthritis of the shoulder

BACKGROUND

Total shoulder arthroplasty infections are rare, depending on the use of antibiotic prophylaxis, the local blood supply, the axial load gradient and the proximal location of the shoulder. The purpose of this study was to evaluate the results of treatment for infections in total shoulder arthroplasty and septic arthritis using a preformed antibiotic-loaded spacer.

MATERIALS AND METHODS

Seven shoulders in as many patients were treated for infected arthroplasty or septic arthritis without previous surgery. A preformed antibiotic-loaded spacer was always applied. Patients were evaluated at the final follow-up with the Constant Score (CS), the Secec Elbow Score (SES), and the American Shoulder and Elbow Society Score (ASESS).

RESULTS

The mean follow-up was 40, 71 months after spacer implant. Infection was always confirmed preoperatively by the leukocyte and neutrophil counts in the aspirated synovial fluid, and intra-operative biopsy and pathologic analysis. Positive bacterial cultures were found in 5 cases: 3 MRSA and 2 Staphylococcus epidermidis. The mean SES increased from 34.43 before spacer implant to 77.29 at final follow-up, ASESS ranged from 14.86 to 21.14, and CS from 40.28 to 79.14.

CONCLUSION

A preformed antibiotic-loaded spacer is intended to release gentamicin alone, but we can consider adding vancomycin to increase antibiotic spectrum. An early diagnosis and an immediate treatment can prevent a persistent infection and severe soft-tissue damage. The use of a preformed antibiotic spacer allows maintaining joint function at the intermediate stage in two-stage treatment.

Resection arthroplasty for failed shoulder arthroplasty

BACKGROUND

As shoulder arthroplasty becomes more common, the number of failed arthroplasties requiring revision is expected to increase. When revision arthroplasty is not feasible, resection arthroplasty has been used in an attempt to restore function and relieve pain. Although outcomes data for resection arthroplasty exist, studies comparing the outcomes after the removal of different primary shoulder arthroplasties have been limited.

MATERIALS AND METHODS

This was a retrospective multicenter review of 26 patients who underwent resection arthroplasty for failure of a primary arthroplasty at a mean follow-up of 41.8 months (range, 12-130 months). Resection arthroplasty was performed for 6 failed total shoulder arthroplasties (TSAs), 7 failed hemiarthroplasties, and 13 failed reverse TSAs.

RESULTS

Patients who underwent resection arthroplasty demonstrated significant improvement in visual analog scale pain score (6 ± 4 preoperatively to 3 ± 2 postoperatively). Mean active forward flexion and mean active external rotation decreased, but this difference was not significant. Subgroup analysis revealed that postoperative mean active forward flexion was significantly greater in patients undergoing resection arthroplasty after failed TSA than after reverse TSA (P = .01).

CONCLUSIONS

Resection arthroplasty is effective in relieving pain, but patients have poor postoperative function. Patients with resection arthroplasty for failed reverse shoulder arthroplasty have worse function than those with failed hemiarthroplasty or TSA. Surgeons should be aware of this when assessing postoperative function. There is no difference in functional outcome between hemiarthroplasty and TSA.

Two-stage reimplantation for treating prosthetic shoulder infections

BACKGROUND

Two-stage reimplantation for prosthetic joint infection reportedly has the lowest risk for recurrent infection. Most studies to date have evaluated revision surgery for infection using an anatomic prosthetic. As compared with anatomic prostheses, reverse total shoulder arthroplasty is reported to have a higher rate of infection.

QUESTIONS/PURPOSES

We determined reinfection rates, functional improvement, types and rates of complications, and influence of rotator cuff tissue on function for two-stage reimplantation for prosthetic joint infection treated with reverse shoulder arthroplasty.

PATIENTS AND METHODS

We retrospectively reviewed 27 patients treated with a two-stage reimplantation for prosthetic shoulder infection using a uniform protocol for management of infection; of these, 17 had reverse shoulder arthroplasty at second-stage surgery. Types of organisms cultured, recurrence rates, complications, function, and radiographic followup were reviewed for all patients.

RESULTS

One of the 17 patients had recurrence of infection. The mean (± SD) Penn shoulder scores for patients treated with reverse shoulder arthroplasty improved from 24.9 ± 22.3 to 66.4 ± 20.8. The average motion at last followup was 123° ± 33° of forward flexion and 26° ± 8° of external rotation in patients treated with a reverse shoulder arthroplasty. The major complication rate was 35% in reverse shoulder arthroplasty, with five dislocations and one reinfection. There was no difference in final Penn score between patients with and without external rotation weakness.

CONCLUSIONS

Shoulder function and pain improved in patients treated with a second-stage reimplantation of a reverse prosthesis and the reinfection rate was low.

LEVEL OF EVIDENCE

Level IV, case series. See Guidelines for Authors for a complete description of levels of evidence.

Infection after shoulder surgery

Infection after shoulder surgery is rare but potentially devastating. Normal skin flora, including Staphylococcus aureus, Staphylococcus epidermidis, and Propionibacterium acnes, are the most commonly isolated pathogens. Perioperative measures to prevent infection are of paramount importance, and clinical acumen is necessary for diagnosis. Superficial infections may be managed with local wound measures and antibiotics; deep infections require surgical débridement in combination with antibiotic treatment. Treating physicians must make difficult decisions regarding antibiotic duration and the elimination of the offending organisms by resection arthroplasty, direct implant exchange, or staged revision arthroplasty. Eradication of a deep infection is usually successful, but the course of treatment is often protracted, and tissue destruction and scar may adversely affect functional outcome.

Management of chronic shoulder infections utilizing a fixed articulating antibiotic-loaded spacer

BACKGROUND

Literature on management of chronic shoulder infections is limited. The purpose of this study was to examine the efficacy of a standardized protocol for the management of chronic shoulder infections, including periprosthetic infections, utilizing an articulating antibiotic-loaded spacer.

MATERIAL AND METHODS

Thirty patients with chronic shoulder infections (4 primary and 26 postoperative) were treated with aggressive debridement, implantation of an antibiotic-loaded articulating spacer, and systemic antibiotics. Twenty-seven patients (90%) were compromised hosts. Eighteen patients (group I) elected to keep the spacer but three patients later underwent reimplantation, thus fifteen patients (group IA) were using the spacer as a prosthesis at their latest follow-up of 2.4 years. Twelve patients (group II, follow-up of 2.3 years) underwent reimplantation of a prosthesis.

RESULTS

Eradication of infection was accomplished in all 30 patients. Group IA patients had a Disability of Arm Shoulder and Hand (DASH) score of 50, Simple Shoulder Test (SST) score of 5, forward flexion of 73 degrees, abduction of 71 degrees, and external rotation of 29 degrees. Group II patients had a DASH score of 58, SST score of 5, forward flexion of 78 degrees, abduction of 83 degrees, and external rotation of 19 degrees. The differences between these 2 groups were not significant.

DISCUSSION

Chronic shoulder infections can be successfully treated with a protocol of aggressive debridement, antibiotic-loaded articulating spacer, and systemic antibiotics. Prolonged implantation of an articulating spacer may be a viable option in select low-demand patients with comorbidities.

Preservation of the shoulder joint by the use of a hybrid-spacer after septic loosening of a reversed total shoulder joint arthroplasty: a case report

Infections of a total joint replacement (TJR) of the shoulder are rare complications. After revision surgery, the incidence rises dramatically. If infection occurs, it leads to a loss of function and may be devastating to the joint. Treatment options range from single- to multiple-staged revision programs, permanent resection arthroplasty or exarticulation. In this case, a reversed shoulder endoprosthesis, which was implanted after multiple revisions of a TJR due to a posttraumatic omarthrosis and rotator cuff insufficiency, got infected. A hybrid-spacer, made of a humeral nail and a custom-made PMMA spacer forming the humeral head, was used during the revision program. After two operations, clinical and paraclinical signs turned back to normal. The patient felt well and was satisfied with the result of the therapy. The hybrid-spacer was then left in situ as a definitive solution with a satisfying range of motion. This case report shows that a hybrid-spacer can be helpful in the treatment of an infected shoulder TJR.

Two-stage shoulder reconstruction for active glenohumeral sepsis

In some circumstances, two-stage reconstruction is recommended for the treatment of glenohumeral sepsis. This study retrospectively reviewed the results in 25 patients after this treatment. Pain was the only consistent preoperative symptom, found in 95% of patients. The most common infecting organisms were coagulase-negative Staphylococcus in 8 cases, Proprionibacterium acnes in 7, and methicillin-sensitive Staphylococcus aureus in 3. Outcomes were reviewed in 21 patients with 2-year minimum follow-up, at an average 4.1 years. Infection was eradicated in 18 of 21 shoulders. Success was related to the specific infecting organism, as all failures were among shoulders infected with Proprionibacterium (P=.0198). Pain was typically relieved, with a mean visual analog pain score of 1.67 at follow-up. Motion was similarly improved, with flexion increased to 100.9 degrees (P<.001), abduction to 93.6 degrees (P<.001), and external rotation 32.6 degrees (P=.0012). Two-stage shoulder reconstruction for infection is typically effective for curing the infection and improving pain and motion; however, function tends to remain limited.

The results of two-stage re-implantation for infected shoulder replacement

While frequently discussed as a standard treatment for the management of an infected shoulder replacement, there is little information on the outcome of two-stage re-implantation. We examined the outcome of 17 consecutive patients (19 shoulders) who were treated between 1995 and 2004 with a two-stage re-implantation for the treatment of a deep-infection after shoulder replacement. All 19 shoulders were followed for a minimum of two years or until the time of further revision surgery. The mean clinical follow-up was for 35 months (24 to 80). The mean radiological follow-up was 27 months (7 to 80). There were two excellent results, four satisfactory and 13 unsatisfactory. In 12 of the 19 shoulders (63%) infection was considered to be eradicated. The mean pain score improved from 4.2 (3 to 5 (out of 5)) to 1.8 (1 to 4). The mean elevation improved from 42 degrees (0 degrees to 140 degrees ) to 89 degrees (0 degrees to 165 degrees ), mean external rotation from 30 degrees (0 degrees to 90 degrees ) to 43 degrees (0 degrees to 90 degrees ), and mean internal rotation from the sacrum to L5. There were 14 complications. Our study suggests that two-stage re-implantation for an infected shoulder replacement is associated with a high rate of unsatisfactory results, marginal success at eradicating infection and a high complication rate.

Shoulder arthroplasty

Shoulder prostheses are now commonly used. Clinical results and patient satisfaction are usually good. The most commonly used types are humeral hemiarthroplasty, unconstrained total shoulder arthroplasty, and semiconstrained inversed shoulder prosthesis. Complications of shoulder arthroplasty depend on the prosthesis type used. The most common complications are prosthetic loosening, glenohumeral instability, periprosthetic fracture, rotator cuff tears, nerve injury, infection, and deltoid muscle dysfunction. Standard radiographs are the basis of both pre- and postoperative imaging. Skeletal scintigraphy has a rather limited role because there is overlap between postoperative changes which may persist for up to 1 year and early loosening and infection. Sonography is most commonly used postoperatively in order to demonstrate complications (hematoma and abscess formation) but may also be useful for the demonstration of rotator cuff tears occurring during follow-up. CT is useful for the demonstration of bone details both pre- and postoperatively. MR imaging is mainly used preoperatively, for instance for demonstration of rotator cuff tears.

Peroxisome proliferator-activated receptors mediate host cell proinflammatory responses to Pseudomonas aeruginosa autoinducer

The pathogenic bacterium Pseudomonas aeruginosa utilizes the 3-oxododecanoyl homoserine lactone (3OC(12)-HSL) autoinducer as a signaling molecule to coordinate the expression of virulence genes through quorum sensing. 3OC(12)-HSL also affects responses in host cells, including the upregulation of genes encoding inflammatory cytokines. This proinflammatory response may exacerbate underlying disease during P. aeruginosa infections. The specific mechanism(s) through which 3OC(12)-HSL influences host responses is unclear, and no mammalian receptors for 3OC(12)-HSL have been identified to date. Here, we report that 3OC(12)-HSL increases mRNA levels for a common panel of proinflammatory genes in murine fibroblasts and human lung epithelial cells. To identify putative 3OC(12)-HSL receptors, we examined the expression patterns of a panel of nuclear hormone receptors in these two cell lines and determined that both peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) and PPARgamma were expressed. 3OC(12)-HSL functioned as an agonist of PPARbeta/delta transcriptional activity and an antagonist of PPARgamma transcriptional activity and inhibited the DNA binding ability of PPARgamma. The proinflammatory effect of 3OC(12)-HSL in lung epithelial cells was blocked by the PPARgamma agonist rosiglitazone, suggesting that 3OC(12)-HSL and rosiglitazone are mutually antagonistic negative and positive regulators of PPARgamma activity, respectively. These data identify PPARbeta/delta and PPARgamma as putative mammalian 3OC(12)-HSL receptors and suggest that PPARgamma agonists may be employed as anti-inflammatory therapeutics for P. aeruginosa infections.

Treatment of primary isolated shoulder sepsis in the adult patient

Isolated shoulder sepsis is an uncommon clinical problem with little information in the literature on causative organisms and potential sequelae. We examined the organisms involved, surgical treatments, antibiotic treatments rendered, and complications in these cases. We retrospectively reviewed the records of 19 adult patients (19 shoulders) who underwent operative treatment of isolated shoulder sepsis from 1996 to 2005. Patient age, gender, laboratory studies, previous treatment, surgical procedures, surgical findings, cultured organism, antibiotic treatment, and complications were reviewed. The organisms included methicillin-susceptible Staphylococcus aureus (five), Streptococcus B beta hemolytic (five), Staphylococcus epidermidis (three), negative cultures (two), Streptococcus viridans (one), Escherichia coli (one), methicillin-resistant S. aureus (one), and Propionibacterium acnes (one). We treated patients with intravenous antibiotics an average of 4.2 weeks (range, 3-8 weeks). One patient underwent humeral head resection with an antibiotic spacer. Another patient died during hospitalization. Open or arthroscopic débridement in conjunction with appropriate antibiotics appears effective in eradicating infection in most adults who present with shoulder sepsis. Functional outcome is poor in those patients with irreparable rotator cuff tears and/or cartilage loss.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

[Treatment of septic arthritis of the shoulder and periprosthetic shoulder infections. Special problems in rheumatoid arthritis]

Infections of the shoulder joint are rare but nevertheless carry a high risk of complications. Successful therapy is mostly operative and should be planned according to the causes, stage, and expansion of the infection and the expected spectrum of bacteria. Moreover, the patient's general condition and previous illnesses must be considered. Patients with rheumatoid arthritis and immunotherapy are especially at risk for complications and require special attention. Shoulder infections and periprosthetic infections can be treated with arthroscopy, with open debridement, or, in the case of periprosthetic infections, with one- or two-stage exchange procedures. In cases of noncontrollable infections, resection arthroplasty or arthrodesis can be performed as a last resort. Results and possible complications are described herein, including those based on our own results.

Prolonged implantation of an antibiotic cement spacer for management of shoulder sepsis in compromised patients

The purpose of this report is to present the preliminary results after treatment of shoulder sepsis with prolonged implantation of an antibiotic-loaded cement spacer in a selected group of compromised patients. The current study included 11 patients (9 men and 2 women) with a mean age of 64 years (range, 36-79 years). All patients were treated with radical débridement, implantation of an antibiotic-impregnated polymethylmethacrylate spacer, and 6 weeks of antibiotic therapy. The subjective complaints, range of motion of the shoulder, functional outcome (mini-Quick Disability of the Arm, Shoulder, and Hand score), and radiographic findings were evaluated. At a mean follow-up of 22 months (range, 15-26 months), 9 patients were free of infection, with pain relief and adequate shoulder function for activities of daily living. Radiographic evaluation revealed no loosening or fracture of the spacer and no progressive degenerative changes involving the glenoid. Prolonged implantation of the spacer may be a useful alternative in selected patients with poor general condition.

[Clinical results of resection arthroplasty for infected shoulder arthroplasty]

PURPOSE OF THE STUDY

Infection is a rare complication of shoulder arthroplasty. Various therapeutic solutions have been proposed: antibiotics alone, one-stage or two-stage reimplantation, surgical or arthroscopic cleaning without prosthesis removal, scapulohumeral arthrodesis or simple arthroscopic resection. We evaluated the mid-term clinical outcome after resection arthroplasty for the treatment of infected shoulder arthroplasty.

MATERIAL AND METHODS

The series included ten infected arthroplasties in ten patients. Mean duration of implantation was two years seven months (range nine months to five years). Bacteriological diagnosis was established from intraoperative articular samples or systematic samples taken during surgical revision procedures: meti-S Staphylococcus aureus strains (n=4), coagulase-negative Staphylococcus (n=5 including three S. epidermidis) Streptococcus mitis (n=1) and Citrobacter koseri (n=1). The mean Constant score before revision was 58 (range 23-77). Subjective patient satisfaction before surgical revision was rated good in six cases, fair in one and poor in three. Surgery associated removal of the implant, complete resection of the cement, resection of the fistular tracts, wide debridement of infected tissues and total synovectomy.

RESULTS

Patients were seen at an average follow-up of three years eight months. The objective functional outcome measured with the Constant score was only fair, 28 points (range 20.6-36), and corresponded to a loss of 29 points compared with the preoperative score. This was explained mainly by lower scores for joint motion, function and muscle force but with persistently satisfactory scores for pain. All patients remained pain-free (daytime and nighttime). Patient satisfaction was rated good for two, fair for five and mediocre for three. Clinical and biological proof of eradicated infection was obtained in all patients.

DISCUSSION

Infection remains a serious devastating problem for shoulder arthroplasty with an important functional impact. Resection only has a modest clinical effect. Precise identification of the causal germ with institution of adapted antibiotic therapy is required for eradication of the infection. Early diagnosis is probably the most important parameter affecting clinical outcome and surgical options. Functional results after resection arthroplasty are modest. This procedure should be reserved for patients with reduced functional demands. Improved management of the infectious load and reduction of diagnostic delay should help improve functional outcome and favor use of stow-stage procedures for reinsertion.

The outcome of resection shoulder arthroplasty for recalcitrant shoulder infections

Postarthroplasty infection is a devastating complication. In some patients, virulent pathogens or poor health complicate reconstruction. Resection arthroplasty is a viable option in such cases. Seven patients with resection arthroplasty following infection after shoulder arthroplasty were reviewed retrospectively at an average 20- month follow-up (range, 12-41). Average time between the initial procedure and the first debridement was 59.5 months (4-151 months). The average number of debridements was 2.2 per patient (range, 1-4 procedures). There were no complications, no recurrence of deep infection, no nerve damage, and no fractures. All patients were able to reach the opposite axilla, their backpocket and perineum, and their mouth. All but 1 patient were satisfied with their result. No patient had a satisfactory outcome via Neer's criteria. Resection arthroplasty is a reasonable salvage option for patients who are not good candidates for prosthetic reimplantation. This yields patients who can reliably perform basic activities of daily living.

Permanent articulated antibiotic-impregnated cement spacer in septic shoulder arthroplasty: a case report

We report a case of a patient with an infected shoulder hemiarthroplasty in whom a permanent antibiotic-impregnated cement spacer was employed with satisfactory results. This method of treatment has limited applications and would not be appropriate in all cases of septic shoulder joint arthroplasties. However, its use may represent a valid alternative in low physical demand patients who are unwilling to undergo major surgery or when inadequate bone stock is present.

Treatment of deep infections of the shoulder with pedicled myocutaneous flaps

Infection after reconstruction of the shoulder can lead to significant morbidity and possible destruction of the glenohumeral joint. Often, seemingly small wound problems mask underlying soft-tissue deficiency and instability. We have reviewed our experience with deep infections of the shoulder that have been treated with pedicled myocutaneous flaps. Patients in this series had been treated by a variety of local measures including debridement and attempts at reclosure, often unsuccessfully. The ability to import well-vascularized tissue that can treat dead space as well as reestablish a new cutaneous envelope around the shoulder is desirable and indicated for these difficult cases. Surprisingly, even with exposure of the humeral head in the wound, the shoulder joint can be salvaged by use of the techniques described in this article.

Staged exchange arthroplasty for shoulder sepsis

Eight patients with shoulder sepsis were treated with staged exchange arthroplasty using antibiotic-impregnated polymethyl methacrylate spacers shaped and fitted to the patient's anatomy after extensive joint débridement. Intravenous antibiotic therapy followed for a minimum of 3 months. At the end of 6 months, the patients were evaluated for any clinical or laboratory signs of infection; none were encountered. Exchange prosthetic reconstructions were performed using standard implants fixed with antibiotic-impregnated polymethyl methacrylate cement. Three patients underwent a revision to total shoulder arthroplasty, whereas 5 underwent hemiarthroplasty of the humerus with local capsular flap covering of the glenoid. All patients experienced substantial pain relief and improvement in function despite limited total overhead motion, showing this technique to be a satisfactory salvage procedure for managing sepsis of the glenohumeral joint primarily and after total shoulder arthroplasty.

Revision of failed total shoulder arthroplasty

The complexity of revision shoulder surgery remains a supreme challenge for the experienced shoulder surgeon. The difficulty of surgery is often accompanied by unpredictable patient cooperation during the postoperative rehabilitation program. Recognition of the problems associated with the failed shoulder arthroplasty is necessary for successful revision surgery. Numerous reconstructive techniques are necessary for restoration of soft tissue and bony deficiencies. Component revision is often necessary in treating component loosening or glenohumeral instability. Glenoid component removal may be necessary in the presence of severe rotator cuff insufficiency or marked glenoid bone deficiency. Humeral revision is most predictably treated with methylmethacrylate fixation. Humeral fractures associated with humeral arthroplasty are most successfully treated surgically, except in those instances where a long oblique or spiral fracture is not associated with prosthetic loosening. Deep infection is most predictably treated by extensive debridement, parenteral antibiotics, and delayed exchange of the components. The success of revision shoulder arthroplasty is often unpredictable, with 60% of revisions offering satisfactory pain relief and restoration of function. Critical to the success of revision arthroplasty is the status of the soft tissues, particularly the anterior deltoid and rotator cuff.